delta bot

A group of embedded developers from Sioux Embedded Systems in Eindhoven, the Netherlands, wanted to get experience working on Microsoft .Net. To make it fun they made it their project to produce a LEGO train with visitors at LEGO World, the official LEGO convention in the Netherlands. The team developed an application in C# to fully automate the train, with Mindstorms NXT and EV3 bricks as well as LEGO Power Functions motors controlling everything.

The train project carries a simple premise: the visitor chooses one of four colors, and the train goes and picks up a piece of simulated candy with the matching color. Called Sioux.net on Track, the project has produced a new train every year since 2012 with improvement goals in place to add features with every version. Ironically, the least interesting part of the setup is the actual train and track. The team’s creativity comes to the fore in two areas of the project: the method by which the candy color is selected, and the assembly that dispenses the correct color into the train car.

Team member [Hans Odenthal] has built candy-grabbers for various years’ trains. He learned about the ABB FlexPicker and this year decided to build a delta robot for the layout. It consists of huge girders constructed from 5×9 and 5×11 Technic beam frames held together with more Technic beams and hundreds of connector pegs. The three arms each move on a pair of turntables which are geared down to provide as much torque as possible — the fake candy pieces are light, but the arms themselves weigh a lot. [Hans] ended up revamping the gearboxes to up the ratio from 1:5 to 1:25.

[Alonso Martinez] is an artist working on virtual characters at Pixar so it’s no wonder that his real life robots, Mira and Gertie, have personalities that make them seem like they jumped straight out of a Pixar movie. But what we really like are the tricks he’s used inside to bring them to life that are sure to get reused for the same or other things.

Mira’s head rotation mechanism

For example, Mira’s head can rotate in yaw, pitch and roll. To figure out how to make it do that he recalled having a joystick called the Microsoft Sidewinder Pro that had force feedback. That meant it might have had motors in line with the motions, much like what he wanted. To see how it worked, he bought one on eBay, took it apart, and improved on it to come up with his own design. But besides making use of the design in joysticks and heads, we can imagine it used to make robot eyeballs rotate in their sockets too. And as a side note, he’s running the robot off a Raspberry Pi, but notice the clever, space-saving way he’s mounted the whole mechanism to the Pi’s four mounting holes.

What also piqued our interest are the two tiny servos used in the head mechanism, two HD-DSM44 digital servos. These are even smaller than Tower Pro SG90s and with the added advantage of being metal geared.

Gertie’s delta jumping legs

To make the eyes blink he had to overcome the fact the head was a thin-walled sphere sliding over the body, and the eyes had to fit in the thin wall without contacting the body. His solution was to make them out of OLED screens with acrylic hemispheres for the protruding eyeballs. The circuit boards talk to the screens through ribbon cables that are around 32 connections per inch, which made for some careful soldering. And to further create a thin profile he even sanded the solder points flat.

His other robot, the yellow and green Gertie, jumps to move around and its internal mechanism is also a joy to examine. To swivel and hop, it uses much the same design as a delta 3D printer, with three legs that can move the upper body in any direction, and compress like a spring before leaping. We like how his method for determining the appropriate thickness of 3D printed PLA parts such that they wouldn’t break was simply trial an error, taking advantage of the rapid prototyping possible with 3D printers. He did cheat on one main part of each leg though, and that was to go with RC car tie rods for the lower half of each leg — but we won’t tell on him if you won’t.

And that’s only a small sample of the neat tips and tricks you’ll find in the video below (they start looking inside the robots at 7:35).

It doesn’t happen that often, but this is the last time that [Lucas] comes back from hours of unattended 3D printing to find a large portion of plastic spaghetti mess and a partly disassembled Kossel. The crash sensor he designed will now safely halt the printer if it detects that something went wrong during the print.

[Massimo Moretti] has a big idea – to build housing on the cheap from locally sourced materials for a burgeoning world population. He also has a background in 3D printing, and he’s brought the two concepts together by building a 12 meter tall delta-bot that can print a house from clay.

The printer, dubbed Big Delta for obvious reasons, was unveiled in a sort of Burning Man festival last weekend in Massa Lombarda, Italy, near the headquarters of [Moretti]’s WASProject. From the Italian-language video after the break, we can see that Big Delta moves an extruder for locally sourced clay over a print area of about 20 square meters. A video that was previously posted on WASProject’s web site showed the printer in action with clay during the festival, but it appears to have been taken down by the copyright holder. Still, another video of a smaller version of Big Delta shows that clay can be extruded into durable structures, so scaling up to full-sized dwellings should be feasible with the 4 meter delta’s big brother.

Clay extrusion is not the only medium for 3D printed houses, so we’ll reserve judgment on Big Delta until we’ve seen it print a livable structure. If it does, the possibilities are endless – imagine adding another axis to the Big Delta by having it wheel itself around a site to print an entire village.

With the advent of cheap PCB fabrication, (relatively) easy to use layout tools, and a whole host of prototypes for nearly any device imaginable, the age of custom circuits is upon us. The tools to make these custom circuits, though, are usually hilariously expensive or simply unavailable to all but the most resourceful hackerspace. It would be great if every workshop in the country had a pick and place machine, and the $300 Pick and Place / 3D printer would be a great way to introduce this tech to millions of electronic tinkerers around the world. It also makes for a great entry to The Hackaday Prize.

The basic design of this machine is a delta bot. This is a wonderful choice over a Cartesian bot; deltas are faster and can have higher acceleration, a great thing to have if you want to throw together a few boards quickly. Although the configuration looks a little inverted as compared to other 3D printer delta bots, there’s a reason for this: the design was simulated with evolutionary algorithms and statistical tests to find the best geometry for the machine. The completed machine should be able to place 0201 components; anything smaller would be called dust.

The software hits all the marks, using OpenCV for image processing, ARM boards for motor control and computational tasks, and a good bit of mechanical and pneumatic work to suck up the parts. They’re even working on a 3D printed tape feeders. Now a component often overlooked when looking at the total cost of pick and place equipment is essentially free.

It’s awesome work, and even if they don’t win The Hackaday Prize, it’s still something every hackerspace should have. Now if someone would only crack the through-hole plating problem…

The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

If you think about it, the RepRaps and other commercial 3D printers we have today are nothing like the printers that will be found in the workshops of the future. They’re more expensive than they need to be, and despite the RepRap project being around for a few years now, no one has cracked the nut of closed loop control yet. [mad hephaestus], [Alex], and [Will] over on the Hackaday Projects site are working on the future of 3D printing with the Servo Stock, a delta printer using servos and closed loop control to build a printer for about a quarter of the price as a traditional 3D printer.

The printer itself is a Kossel derivative that is highly modified to show off some interesting tech. Instead of steppers, the printer has three axes controlled by servos. On each axis is a small board containing a magnetic encoder, and a continuous rotation servo. With this setup, the guys are able to get 4096 steps per revolution with closed loop control that can drive the servo to with ±2 ticks.

The electronics and firmware are a clean sheet redesign of the usual 3D printer loadout. The motherboard uses a Pic32 running at 80MHz. Even the communication between the host and printer has been completely redesigned. Instead of Gcode, the team is using the Bowler protocol, a system of sending packets over serial, TCP/IP, or just about any other communications protocol you can think of.

Below is a video of the ServoStock interpreting Gcode on a computer and sending the codes and kinematics to the printer. It seems to work well, and using cheap servos and cut down electronics means this project might just be the first to break the $200 barrier for a ready to run 3D printer.

We love home theater hacks and this one especially since it is also part of a larger home automation project. [Falldeaf] use Z-Wave wireless home automation and includes mains switching for his television. The only problem being that when power is switch back on the TV remains in the standby state. His solution was to use an ATtiny85 to detect power, then push the IR code to turn the TV on after a short delay.

Most folks have a smartphone and you can bet that the handsets are Bluetooth enabled. But we think there is still a low percentage who are connecting their smartphone audio to wireless speakers. [Anton Veretenenko] shows how you can use some cheap KRC-86B modules from Ali Express to make your own wireless speakers. He’s even powering his hack with a single 18650 Li-Ion cell.

Taking a turn away from electronics we got a chuckle out of [CADFood’s] plan to make pearls with his bicycle. He used DesignSpark Mechanical to model what amounts to a bicycle powered ball mill. It attaches to his spokes and after taking a hammer to some oyster shells he loads them up and goes for a ride. Well actually he needs to go for a bunch of rides. The idea is that about six months of bicycling will yield a cache of pearls. [Thanks Holger]